下载中心模块和异步导出功能

backend/dvadmin/system/models.py

@@ -1,5 +1,7 @@
 import hashlib
 import os
+from time import time
+from pathlib import PurePosixPath
 
 from django.contrib.auth.models import AbstractUser, UserManager
 from django.db import models
@@ -595,3 +597,41 @@ class MessageCenterTargetUser(CoreModel):
         db_table = table_prefix + "message_center_target_user"
         verbose_name = "消息中心目标用户表"
         verbose_name_plural = verbose_name
+
+
+def media_file_name_downloadcenter(instance:'DownloadCenter', filename):
+    h = instance.md5sum
+    basename, ext = os.path.splitext(filename)
+    return PurePosixPath("files", "dlct", h[:1], h[1:2], basename + '-' + str(time()).replace('.', '') + ext.lower())
+
+
+class DownloadCenter(CoreModel):
+    TASK_STATUS_CHOICES = [
+        (0, '任务已创建'),
+        (1, '任务进行中'),
+        (2, '任务完成'),
+        (3, '任务失败'),
+    ]
+    task_name = models.CharField(max_length=255, verbose_name="任务名称", help_text="任务名称")
+    task_status = models.SmallIntegerField(default=0, choices=TASK_STATUS_CHOICES, verbose_name='是否可下载', help_text='是否可下载')
+    file_name = models.CharField(max_length=255, null=True, blank=True, verbose_name="文件名", help_text="文件名")
+    url = models.FileField(upload_to=media_file_name_downloadcenter, null=True, blank=True)
+    size = models.BigIntegerField(default=0, verbose_name="文件大小", help_text="文件大小")
+    md5sum = models.CharField(max_length=36, null=True, blank=True, verbose_name="文件md5", help_text="文件md5")
+
+    def save(self, *args, **kwargs):
+        if self.url:
+            if not self.md5sum:  # file is new
+                md5 = hashlib.md5()
+                for chunk in self.url.chunks():
+                    md5.update(chunk)
+                self.md5sum = md5.hexdigest()
+            if not self.size:
+                self.size = self.url.size
+        super(DownloadCenter, self).save(*args, **kwargs)
+
+    class Meta:
+        db_table = table_prefix + "download_center"
+        verbose_name = "下载中心"
+        verbose_name_plural = verbose_name
+        ordering = ("-create_datetime",)